1. Field
The following description relates generally to wireless communications, and more particularly to establishing synchronization and/or mitigating interference with a time division duplexing (TDD) access point base station in a wireless communication environment.
2. Background
Wireless communication systems are widely deployed to provide various types of communication content such as, for example, voice, data, and so on. Typical wireless communication systems can be multiple-access systems capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, . . . ). Examples of such multiple-access systems can include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, and the like. Additionally, the systems can conform to specifications such as third generation partnership project (3GPP), 3GPP long term evolution (LTE), ultra mobile broadband (UMB), and/or multi-carrier wireless specifications such as evolution data optimized (EV-DO), one or more revisions thereof, etc.
Generally, wireless multiple-access communication systems can simultaneously support communication for multiple user equipments (UEs). Each UE can communicate with one or more base stations via transmissions on forward and reverse links. The forward link (or downlink) refers to the communication link from base stations to UEs, and the reverse link (or uplink) refers to the communication link from UEs to base stations. Further, communications between UEs and base stations can be established via single-input single-output (SISO) systems, multiple-input single-output (MISO) systems, multiple-input multiple-output (MIMO) systems, and so forth. In addition, UEs can communicate with other UEs (and/or base stations with other base stations) in peer-to-peer wireless network configurations.
Heterogeneous wireless communication systems commonly can include various types of base stations, each of which can be associated with differing cell sizes. For instance, macro cell base stations typically leverage antenna(s) installed on masts, rooftops, other existing structures, or the like. Further, macro cell base stations oftentimes have power outputs on the order of tens of watts, and can provide coverage for large areas. The access point base station is another class of base station that has recently emerged. Access point base stations are commonly designed for residential or small business environments, and can provide wireless coverage to UEs using a wireless technology (e.g., 3GPP Universal Mobile Telecommunications System (UMTS) or LTE, 1×Evolution-Data Optimized (1×EV-DO), . . . ) to communicate with the UEs and an existing broadband Internet connection (e.g., digital subscriber line (DSL), cable, . . . ) for backhaul. An access point base station can also be referred to as a Home Evolved Node B (HeNB), a Home Node B (HNB), a femto cell, a femto cell base station, or the like. Examples of other types of base stations include pico cell base stations, micro cell base stations, and so forth.
According to an example, an access point base station can implement time division duplexing (TDD). The access point base station employing TDD can transmit (e.g., via a downlink, . . . ) and receive (e.g., via an uplink, . . . ) using a common frequency band at different times. Moreover, disparate base station(s) (e.g., disparate access point base station(s), disparate macro cell base station(s), any disparate type of base station(s), . . . ) positioned nearby to the access point base station can similarly use the common frequency band to transmit (e.g., over the downlink, . . . ) and receive (e.g., over the uplink, . . . ). However, if the access point base station lacks synchronization with the disparate base station(s) positioned nearby (or a subset thereof), then interference can result. For instance, if the access point base station and a neighboring macro cell base station are unsynchronized in time, then the access point base station can transmit while the neighboring macro cell base station is receiving, or vice versa. Hence, significant interference due to downlink/uplink jamming can be experienced under such a scenario where the access point base station lacks synchronization with disparate base station(s) located within vicinity.